JUCE/modules/juce_audio_processors/utilities/juce_AudioParameterFloat.h

/*
  ==============================================================================

   This file is part of the JUCE 7 technical preview.
   Copyright (c) 2022 - Raw Material Software Limited

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For the technical preview this file cannot be licensed commercially.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

/** Properties of an AudioParameterFloat.

    @see AudioParameterFloat(), RangedAudioParameterAttributes()
*/
class AudioParameterFloatAttributes : public RangedAudioParameterAttributes<AudioParameterFloatAttributes, float> {};

//==============================================================================
/**
    A subclass of AudioProcessorParameter that provides an easy way to create a
    parameter which maps onto a given NormalisableRange.

    @see AudioParameterInt, AudioParameterBool, AudioParameterChoice

    @tags{Audio}
*/
class JUCE_API  AudioParameterFloat  : public RangedAudioParameter
{
public:
    /** Creates a AudioParameterFloat with the specified parameters.

        Note that the attributes argument is optional and only needs to be
        supplied if you want to change options from their default values.

        Example usage:
        @code
        auto attributes = AudioParameterFloatAttributes().withStringFromValueFunction ([] (auto x, auto) { return String (x * 100); })
                                                         .withLabel ("%");
        auto param = std::make_unique<AudioParameterFloat> ("paramID", "Parameter Name", NormalisableRange<float>(), 0.5f, attributes);
        @endcode

        @param parameterID         The parameter ID to use
        @param parameterName       The parameter name to use
        @param normalisableRange   The NormalisableRange to use
        @param defaultValue        The non-normalised default value
        @param attributes          Optional characteristics
    */
    AudioParameterFloat (const ParameterID& parameterID,
                         const String& parameterName,
                         NormalisableRange<float> normalisableRange,
                         float defaultValue,
                         const AudioParameterFloatAttributes& attributes = {});

    /** Creates a AudioParameterFloat with the specified parameters.

        @param parameterID         The parameter ID to use
        @param parameterName       The parameter name to use
        @param normalisableRange   The NormalisableRange to use
        @param defaultValue        The non-normalised default value
        @param parameterLabel      An optional label for the parameter's value
        @param parameterCategory   An optional parameter category
        @param stringFromValue     An optional lambda function that converts a non-normalised
                                   value to a string with a maximum length. This may
                                   be used by hosts to display the parameter's value.
        @param valueFromString     An optional lambda function that parses a string and
                                   converts it into a non-normalised value. Some hosts use
                                   this to allow users to type in parameter values.
    */
    [[deprecated ("Prefer the signature taking an Attributes argument")]]
    AudioParameterFloat (const ParameterID& parameterID,
                         const String& parameterName,
                         NormalisableRange<float> normalisableRange,
                         float defaultValue,
                         const String& parameterLabel,
                         Category parameterCategory = AudioProcessorParameter::genericParameter,
                         std::function<String (float value, int maximumStringLength)> stringFromValue = nullptr,
                         std::function<float (const String& text)> valueFromString = nullptr)
        : AudioParameterFloat (parameterID,
                               parameterName,
                               std::move (normalisableRange),
                               defaultValue,
                               AudioParameterFloatAttributes().withLabel (parameterLabel)
                                                              .withCategory (parameterCategory)
                                                              .withStringFromValueFunction (std::move (stringFromValue))
                                                              .withValueFromStringFunction (std::move (valueFromString)))
    {
    }

    /** Creates a AudioParameterFloat with an ID, name, and range.
        On creation, its value is set to the default value.
        For control over skew factors, you can use the other
        constructor and provide a NormalisableRange.
    */
    AudioParameterFloat (const ParameterID& parameterID,
                         const String& parameterName,
                         float minValue,
                         float maxValue,
                         float defaultValue);

    /** Destructor. */
    ~AudioParameterFloat() override;

    /** Returns the parameter's current value. */
    float get() const noexcept                  { return value; }

    /** Returns the parameter's current value. */
    operator float() const noexcept             { return value; }

    /** Changes the parameter's current value. */
    AudioParameterFloat& operator= (float newValue);

    /** Returns the range of values that the parameter can take. */
    const NormalisableRange<float>& getNormalisableRange() const override   { return range; }

    /** Provides access to the parameter's range. */
    NormalisableRange<float> range;

protected:
    /** Override this method if you are interested in receiving callbacks
        when the parameter value changes.
    */
    virtual void valueChanged (float newValue);

private:
    //==============================================================================
    float getValue() const override;
    void setValue (float newValue) override;
    float getDefaultValue() const override;
    int getNumSteps() const override;
    String getText (float, int) const override;
    float getValueForText (const String&) const override;

    std::atomic<float> value;
    const float valueDefault;
    std::function<String (float, int)> stringFromValueFunction;
    std::function<float (const String&)> valueFromStringFunction;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (AudioParameterFloat)
};

} // namespace juce